JP2501959B2 - Infrared ranging camera - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared distance measuring camera, and more particularly to an infrared distance measuring device which measures a distance to a subject by using infrared rays and adjusts the focus, and remotely controls the operation of the camera by an infrared remote controller. Cameras.

[0002]

2. Description of the Related Art At present, there is an infrared distance measuring method as one means for automatically adjusting the focus of a camera. Further, infrared remote control means for remotely controlling the device from a remote place is applied to equipment such as a television, a video or an air conditioner.

By the way, for example, in recent home video cameras, there is a highly convenient product that can be remotely operated by a remote controller by mounting an infrared remote sensor together with an automatic focusing mechanism based on the infrared distance measuring method. It is being marketed.

However, when distance measurement and remote control are performed using the same infrared rays as described above, if infrared rays having similar wavelengths are used, mutual interference may occur and distance measurement and control signal transmission may not be performed accurately. There is. For this reason, conventionally, the wavelengths of infrared rays for distance measurement and remote control are changed, light is received by light receiving elements matching the respective wavelengths, and signal processing is individually performed by each signal processing system.

This conventional infrared distance measuring camera will be described with reference to the drawings.

For example, FIGS. 9A and 9B are external views of a home video camera, in which FIG. 9A shows a camera body and FIG. 9B shows a remote controller.

The main body (100) of the video camera shown in FIG.
The focus ring (101) is for moving a focus lens group (not shown) to focus the subject image incident from the optical lens (102). In this focus ring (101), infrared rays are projected onto an object from an infrared ray emitting element (not shown) on the main body side, and reflected light is received by an infrared ray receiving element in an autofocus distance measuring window (103) to perform distance measurement. , Is driven based on the measured distance value.

Further, in the infrared remote controller (104) of FIG. 2B, an infrared control signal corresponding to each switch (105) is projected from the light projecting window (106), and the remote sensor of FIG. The light is received at (107) and the video camera is remotely operated.

The structure and operation of the conventional infrared distance measuring mechanism and remote control mechanism will be described below.

The infrared distance measuring mechanism is shown in FIG. Here, the distance from the light projecting lens (108) and the light receiving lens (109) to the subject (110) is indicated by L, the diameter of the light projecting lens (108) is g, and the diameter of the light receiving lens (109) is φ. The focal length is f. Further, a base line length between the optical axes of the light projecting lens (108) and the light receiving lens (109) is indicated by s, and an infrared light receiving element (Positi) is located behind the light receiving lens (109) by a focal length f.
on Sensitive Device, hereinafter PSD
(111) is arranged. And PSD
An optical filter (112) for selectively passing infrared rays is provided on the light receiving surface of (111).

Further, behind the light projecting lens (108),
Infrared light emitting diode for distance measurement (Light-emiti
ng Diode (hereinafter referred to as LED) (113) is arranged.

At the time of distance measurement, the infrared ray LED (1
Infrared rays are projected onto the subject (110) through the light projecting lens (108) from the light receiving lens (1).
09) through the PSD (111) located at the focal position
An image is formed as a spot light on the light-receiving surface of, and the outputs I1 and I2 at both ends of the PSD change depending on the center position of the spot light (the position deviated from the center of the PSD of FIG. 10 by d). FIGS. 11A and 11B show the relationship with the output current values I1 and I2 corresponding to the light receiving position of the PSD (111). The equivalent circuit diagram of the PSD is shown in FIG. 7C, in which the left and right current division resistance values R1 and R2 change depending on the position p of the spot light, and the output current values from the electrodes A and B at both ends accordingly. I1 and I2 change.

That is, I1 = I2 when the spot light hits the central position o of the PSD, and I1 when it shifts to the right.
1 <I2, shift to the left I1> I2, I1 and I2
The rate of increase / decrease is proportional to the distance d from the center of the PSD as shown in FIG. Therefore, the value of I2 / I1 is not influenced by the intensity of the spot light and is determined by the position of the spot light. The infrared distance measuring mechanism measures the subject distance L using the linear relationship between the PSD spot light position and the output current value thereof as described above. Specifically, f / L = d / s (1) is obtained from the similarity relationship of the triangles shown in FIG. 10, and the output current value I1 of the PSD is calculated using this equation (1).
, I2 is as follows: I1 = K (c / 2-d) = K {c / 2- (f / L) .s} (2) I2 = K (c / 2 + d) = K {c / 2 + (F / L) · s} (3) Note that K in the equations (2) and (3) is a proportional constant. Therefore, from equations (2) and (3), I2 / I1 = {c / 2 + (f / L) .s} / {c / 2- (f / L) .s} = {(c / 2). L + f · s} / {(c / 2) · L−f · s} (4) From the equation (4), it is understood that the relationship between I2 / I1 and the subject distance L is such that an output proportional to 1 / L is obtained as shown in FIG.

Therefore, I2 / I1 is measured, the object distance L is calculated, and the video camera (1
By rotating the focus ring (101) of (00), the subject can be focused.

The distance measuring operation described above is performed by the signal processing / arithmetic circuit (114), sample / hold, analog / digital conversion circuit (115), control circuit (116) and LED drive circuit (117) shown in FIG. Done.

Here, the output of the distance measurement start switch (118) shown in the lower right of FIG.
16).

As shown in FIG. 13, the control circuit (116) is connected to a single pulse generation circuit (119) surrounded by a chain line by a distance measurement start switch (118), and its output is an LED drive pulse (120). ), The LED drive circuit (117) is driven. The NAND gate (12) of the input section of this single pulse generation circuit (119)
Reference numerals 1) and (122) are RS flip-flops for preventing chattering, and the output thereof is given to the JK input of a two-stage shift register composed of dual JK flip-flops (123) and (124).

Here, this control circuit (116)
Generates a reference clock with an oscillator (125) and operates synchronously based on this, and the reference clock is 1 / n
It is frequency-divided by the frequency divider (126) and is supplied to the flip-flops (123) and (124).

Therefore, the output of the flip-flop (123) is synchronized with the first clock pulse coming after the input is generated, and the flip-flop (12) of the subsequent stage is synchronized.
The output of 4) is delayed by one cycle from the output of (123), the Q output of (123) and the Q output of (124) are added to the NAND gate (127), and a single pulse synchronized with the clock pulse is generated. Is obtained. This LED drive pulse (120) is the LED drive circuit (11) shown in FIG.
7) and the LED (113) is turned on.

LED drive circuit (117) (see FIG. 10)
As shown in FIG. 14, a PNP transistor (1
When the above single pulse is applied to the base of 28), a current flows, the base potential of the NPN transistor (129) at the next stage is raised, and a current flows to the LED (113) connected to the collector of the transistor (129). Lighting is performed.

The infrared rays emitted by the lighting of the LED (113) are, as shown in FIG.
PS through the subject (110) and the light receiving lens (109)
It is focused on D (111). The output currents I1 and I2 of the PSD (111) are respectively preamplifiers (130) and (1
In 31), it is converted into a voltage and amplified.

The output of each preamplifier is the log amplifier (13) of the signal processing / arithmetic circuit (114) shown in FIG.
2) and (133), respectively, and the output of the log amplifier is further subtracted by the differential amplifier (136) via the buffer amplifiers (134) and (135).
The ratio Ln (I2 / I1) of 1 to I2 is obtained.

The output of the differential amplifier (136) is shown in FIG.
It is input to the sample / hold (S / H) and analog / digital (A / D) conversion circuit (115) at the next stage shown in FIG. The output of this differential amplifier (136) is the LE described above.
A pulse for sampling and holding only a necessary signal is generated in the control circuit (116) (see FIG. 13) because it appears after a certain time delay from the D drive pulse. That is, the LED drive pulse (1
20) is input to the reset terminal of the preset counter (138) through the inverter (137) in the figure, and when this reset pulse is input, counting is performed for the number of clocks set by the preset value, and the sample hold is performed. A pulse (139) is output.

In the S / H circuit (140) of FIG. 16, the analog value is input to the next A / D conversion circuit (141) and converted into digital data. This A / D conversion circuit (14
As the sampling clock (142) of 1), the reference clock generated by the oscillator (125) shown in FIG. 13 is used. Then, in the A / D conversion circuit (141) of FIG.
PSD converted to bit digital data (143)
The output current ratio I2 / I1 of the latch (144) in FIG.
It is input to and latched so that it can be read by the microcomputer that controls the autofocus. The latched distance measurement output (145) digital data is converted into a subject distance L in a microcomputer (not shown), and the focus lens group is driven according to the value to perform focus control. .

Further, conventionally, a remote control mechanism is provided separately from the infrared distance measuring mechanism.

The remote control mechanism has a pulse pattern (FIG. 18) corresponding to each switch (105) from the projection window (106) of the remote controller (104) shown in FIG.
(See (a)). As shown in FIG. 18 (a),
As the first parity bit (start bit), the infrared light emitting element is turned on in a certain cycle, turned off for a certain period, and then the n-bit data is turned on “1” and turned off “0” to blink the infrared light emitting element. Assuming that the zoom-in of the camera is "0001" and the zoom-back is "0010" as the 4-bit control instruction code, when it is "1", the light is emitted for a certain period at a certain period, so that Control command data can be transmitted using a remote controller. The transmitted infrared signal is shown in FIG.
The remote sensor (1) of the video camera (100) of (a)
The light is received at 07).

In the remote sensor circuit, as shown in FIG. 17, the output signal received by the phototransistor (146) and amplified by the amplifier (147) has the waveform of FIG. 18 (b). In this waveform, the level fluctuation due to external light and the signal from the infrared remote controller coexist, and a low-pass filter (148) for level detection at the next stage is provided, and the sledge hold shown in FIG. Waveform shaping circuit (1
By providing 49), the same pulse pattern as that of the remote controller shown in FIG. 18D can be obtained. This pulse pattern is input to a control circuit such as a microcomputer (not shown) to be decoded, and the video camera is controlled according to the instruction code.

[0028]

As described above, in the conventional infrared ranging camera, the infrared receiving section for distance measurement and the infrared receiving section for remote control are separately arranged, so that the installation space is small. You need two places,
There is also a problem that the cost of the light receiving sensor is high.

Therefore, for example, JP-A-63-155037
In the publication, one light receiving element is used for both reception of infrared rays for distance measurement and control, thereby reducing the installation space of the light receiving element and downsizing the camera.

However, in the case where one light receiving element is also used to receive infrared rays for distance measurement and control as described above, the sensitivity characteristic of the infrared light receiving element is limited to a narrow wavelength range, so that it is not used for distance measurement. It is necessary to make the wavelengths of infrared rays for control substantially the same. Then, when the infrared rays for distance measurement and the infrared rays for control are received by the light receiving element at the same time, both signals may interfere with each other, and as a result, the camera malfunctions.

The present invention has been made to solve the above problems, and an object thereof is to provide an infrared receiving unit for distance measurement and a remote control without impairing the distance measurement function and the remote control function. It is an object of the present invention to provide an infrared range-finding type camera that can be configured with an infrared ray receiving section for use as a single light receiving section.

[0032]

In order to solve the above-mentioned problems, the present invention provides a camera body having a mechanism for transmitting and receiving infrared rays for distance measurement and focusing, and a camera body provided separately from the camera body. An infrared remote controller for transmitting control information for remote control of the camera body to which remote control information for the camera body to which the distance measurement / control processing priority information is added by infrared rays, the camera body including: co infrared receiving element you receiving a control for infrared from the infrared remote controller and the distance measuring infrared, including the distance measuring / control processing priority information from the output signal of the common infrared light receiving element
The control information extraction means for extracting the control information, and the mode determination for determining the distance measurement processing priority mode or the control processing priority mode based on the distance measurement / control processing priority information of the extracted control information. Means, and said infrared
Distance control or control processing priority on the line remote controller side
The feature is that the destination can be selectively set .

[0033]

According to the above construction, the shared infrared light receiving element of the camera body receives the distance measuring infrared light and the control infrared light, and the control information extracting means extracts the control information from the output signal thereof. Then, the mode determination means determines whether the distance measurement process has priority or the control process has priority based on the distance measurement / control process priority information included in the control information, and preferentially processes one of them. Therefore, even if both signals are received at the same time,
This is reliably separated and processed one by one according to the priority order, so there is little malfunction due to interference, small size,
It can be a low-cost infrared ranging camera.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of an infrared distance measuring camera to which the present invention is applied will be described below with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

The infrared distance measuring circuits (114), (1
The configurations of 15) and (116) are the same as those of the conventional example, and thus redundant description will be omitted.

The infrared remote controller (1)
Is a conventional infrared receiver for distance measurement (PSD here)
The control signal for the camera is sent using the wavelength range that can be received by (111), that is, the same infrared ray as the wavelength for distance measurement. Here, the reason why the wavelengths of the light emitting elements for distance measurement and the remote control are made substantially equal is that the sensitivity characteristics of the light receiving elements are not wide with respect to the wavelength, and it is necessary to use the light receiving elements in common. It is a matter.

Therefore, the specific structure of the infrared remote controller (1) has a switch (5) corresponding to a desired camera operation as shown in FIG. 1, and the infrared remote controller (1) is adapted by pressing the switch (5). A pulse signal is emitted from the pulse generator (6). Then, the infrared LED (8) is driven by the LED drive circuit (7) of FIG. 1 in accordance with this pulse signal, and infrared rays in the above wavelength range are emitted to send a signal. In this embodiment, in the palace generator (6), the distance measurement / control process priority serving as a criterion for determining which process has priority when the distance measurement signal and the control signal are superimposed on the first 1 bit of the control information. Information is added.

Now, the control signal detection circuit (2) has P
This is for extracting the output component of the control signal from the outputs of the infrared distance measurement signal received by the SD (111) and the control signal.

Specifically, I1 and I from both ends of the PSD
2 Outputs of preamplifier (130), (13
The signal is amplified in 1), and its output is branched and input to the control signal detection circuit (2).

Then, as shown in FIG. 2, the signals from the preamplifiers (130) and (131) are added by the adder (9) in the control signal detection circuit (2). This is
As shown in, the light receiving position of the control signal from the infrared light emitting means (1) for remote control is PSD (111).
If the signal output of either I1 or I2 becomes large and the signal output of the other becomes small when the center is shifted by x, and if the infrared remote controller (1) is far away,
Since the signal outputs of I1 and I2 both become small and the S / N ratio deteriorates, both signals are added by the adder (9) to reliably perform signal extraction.

Further, this signal is a low pass filter (LP
By passing through F) (10) and the waveform shaping circuit (11), the same pulse pattern as the signal output from the infrared remote controller (1) can be reproduced.

As described above, when one PSD (111) is shared and the control signal and the distance measurement signal are simultaneously received, the signal processing / arithmetic circuit (114) shown in FIG. A distance signal (12) is output, and a remote control signal (13) is output from the control signal detection circuit (2).
Is output.

Here, the control signal (13) for remote control is, as shown in FIG. 1, the decoder (3).
And the signal processing control circuit (4).

The decoder (3) shown in FIG. 3 uses a shift register here and converts serial data sent from the infrared remote controller (1) into parallel data corresponding to a control instruction code. .

Further, the signal processing control circuit (4) shown in FIG. 1 gives priority to one of the signals when the distance measuring signal and the control signal are received in duplicate by the infrared light receiving element. The signal is processed and the other signal processing is stopped to prevent interference. The specific contents of the circuit are shown in FIG.

Further, in another embodiment of the signal control processing circuit (4), in the circuit configuration shown in FIG. 5, control information added with the distance measurement / control processing priority information issued from the infrared remote controller (1) described above. Based on the above, the camera body side is provided with a mode determination circuit (31) for appropriately determining the distance measurement processing priority mode or the control processing priority mode.
In this embodiment, any signal is preferentially processed according to the mode determination circuit (31) to prevent interference between the distance measurement signal and the control signal.

Next, the structure and operation of the infrared distance measuring camera will be described in more detail. Since the distance measuring operation using infrared rays is the same as the above-mentioned conventional example, redundant description will be omitted.
The control operation by the remote control and the signal processing operation when the distance measurement signal and the control signal are superimposed will be mainly described.

As shown in FIG. 1, the infrared rays from the infrared light emitting means (1) for remote control are PSD through the light receiving lens (109) like the infrared rays for distance measurement.
The light is received by the light receiving surface of (111).

First, since the video camera is used under outdoor or indoor illumination, it is necessary to distinguish the external light from the beam light of the infrared LED for distance measurement or control. Therefore, in this embodiment, the infrared LED for distance measurement and control is used.
In this case, the infrared ray having a wavelength of 800 to 950 nm is emitted, and the PSD (111) is also made to receive the infrared ray in the wavelength range.

Further, in front of the light receiving surface of the PSD (111), an optical filter (112) for cutting visible light is provided.
However, it is difficult to distinguish it from the light of the sun or incandescent lamp, etc., so here, the infrared LED for distance measurement and control is pulse-driven or AC-lit to extract only the change. To distinguish from outside light.

Next, the PSD (111) of this embodiment also serves as an infrared light receiving portion for distance measurement and control. For this reason,
If the spot light position of the infrared beam for control is imaged on the light receiving surface of the PSD (111) at the position x from the center,
Depending on the position, I1 and I from both ends of PSD (111)
2 is output. However, the control signal used for remote control is not the position of the spot light unlike the signal at the time of distance measurement, and does not exist during the period (logic "1") in which a pulsed signal exists as shown in FIG. 18B. Since the control command code is transmitted in combination with the period (logic “0”), it is sufficient to determine whether the signal component is “1” or “0”. Therefore, the preamplifiers (130), (13
The outputs of I1 and I2 amplified in 1) are added by the adder (9) of the control signal detection circuit (2), and then the control signal is detected by the low pass filter (10) and the waveform shaping circuit (11). . Therefore, reliable and stable signal extraction can be performed regardless of the image formation position of the spot light.

The control signal (13) having a pulse pattern substantially similar to that shown in FIG. 18D is reproduced by the decoder (3) and the signal processing control circuit (4) at the next stage shown in FIG. Each is entered.

Therefore, as shown in FIG. 4, the control signal (13) consisting of the reproduced serial data is input to the counter 2 (14) of the signal processing control circuit (4). This counter 2 (14) counts a specified number of reference clocks of FIG. 7 (a) from the rising edge of the start bit in the pulse pattern of the serial data shown in FIG. 7 (b), and outputs an output pulse (15 ) To the next counter 3 (1
Output to 6). The reference clock (142) is shown in FIG.
The clock pulse output from the oscillator in the control circuit (116) is used. In this counter 2 (14), the first bit position of the data bit is determined and the start trigger pulse (1
I am making 5).

In the next counter 3 (16), the counter 2
When the start trigger pulse (15) from (14) is input, the reference clock (142) is counted by a specified number and a pulse corresponding to the next data bit is output. Since such operations are performed one after another and the serial data is converted into parallel data by the next decoder, a shift clock as shown in FIG. 7C is created.

The shift clock (17) is input to the monomulti 1 (18) and the counter 4 (19), respectively. Then, the counter 4 (19) counts the shift clock (17) by the revised number of data bits and outputs a pulse (20) indicating the end of the data when the last n-th bit is input (FIG. 7 ( See d)). With this output pulse, a latch pulse (22) for latching parallel data is created in the next stage monomulti 2 (21) (see FIG. 7E).

On the other hand, the output pulse (17) of the counter 3 (16) is also input to the monomulti 1 (18) and has a logic "0" during the period from the first data bit position to the last data bit position of serial data. Is output. The output pulse (FIG. 7 (f)) of the monomulti 1 (18) is input to the counter 2 (14), and the counting operation of the counter 2 (14) is prohibited during the period of logic "0". This pulse is also output to one input terminal of the AND gate (23), and thereby the start bit of the serial data control signal (13) shown in FIG. 7 (b) input to the other input terminal. And the stop bit are output, and the reset pulse (24) of the shift register of the decoder (3) at the next stage is output.
Has been created. (FIG.7 (g)).

The counter 1 (25) has a reference clock (14) shown in FIG.
2) and the LED drive pulse (120) shown in FIG. 6D are input, and the counter 1 (25) is an LED for distance measurement.
The pulse of the enable signal (26) of FIG. 6 (g) showing a series of infrared distance measuring operation period from the light emission of to the end of latching the distance measuring data is generated and output to the decoder (3). There is. The enable signal (26) controls the decoder (3) so that the control signal from the infrared remote controller is not processed during the distance measuring operation, that is, during the disable period, and the distance measuring signal and the control signal are combined. This is to prevent interference.

By the way, in the embodiment of the signal control processing circuit (4), the distance measurement signal is processed with priority over the control signal. This is because it is better for the control signal of the switch for zooming and recording start to be turned on from the in-focus state by the distance measurement signal of autofocus, so it is suitable to prioritize the distance measurement signal over the control signal. Is. However, it may be better to process the control signals of switches such as the power on / off switch and the recording stop switch that are not directly related to the autofocus, prior to the ranging signal. In this way, when the priority processing order of the distance measurement signal and the control signal is appropriately changed according to the processing operation, another configuration as shown in FIG. 5 is adopted.

In this case, the distance measurement / control which is included in the first 1 bit of the data bits (n bits) of the serial data shown in FIG. 7B and which determines the distance measurement processing priority mode or the control processing priority mode. The processing priority information is used as a criterion.
Then, the distance measuring / control processing priority information is judged by the mode judging circuit (31) in FIG.

In FIG. 5, a mode judging circuit (31)
Is composed of a NAND gate (32) and an AND gate (33). Then, the start trigger pulse (15) from the counter 2 (14) and the serial data (13) from the control signal detection circuit (2) are input to the input side of the NAND gate (32). (13)
Only when both (1) and (15) are "1", "0" is output from the output side. That is, when the first 1-bit ranging / control processing priority information is "1", the control processing priority mode is set, and "0" is output from the NAND gate (32).

On the input side of the AND gate (33), the output of the NAND gate (32) and the counter 1
The enable signal (26) of FIG. 6 (g) showing the infrared distance measuring operation period from (25) is input. As a result, when the priority information is "1" and the distance measurement signal and the control signal are superimposed, "0" is always input as the enable signal (34) to the decoder (3) in FIG. As a result of being disabled, the control signal is preferentially processed.

On the other hand, when the first 1-bit ranging / control processing priority information is "0", the ranging processing priority mode is set, and N
"1" is output from the AND gate (32).

Then, to the input side of the AND gate (33), "1" from the counter 1 (25) and the input "1" from the NAND gate (32) are input during the infrared distance measuring operation. To be done. In this way, the priority information is "0".
If the distance measurement signal and the control signal are superposed, "1"
Is input as an enable signal (34) to the decoder (3) in FIG. 3, the shift register is enabled, and as a result, the ranging signal is preferentially processed.

Thus, in the case of the embodiment shown in FIG. 5,
The control processing priority mode and the distance measurement processing priority mode can be appropriately selected and processed by a signal from the infrared remote controller (1). In addition to this, a switch for priority mode is provided on the camera body side,
It is also possible to configure to select appropriately.

By inputting each pulse to the shift register of the decoder (3) as described above, the data bit consisting of n bits in the serial data sent from the remote controller is controlled except during the distance measuring operation period. It is output after being converted into parallel data of instruction code. The shift register is, for example, M66 manufactured by Mitsubishi Electric Corporation.
An IC such as 312P is used.

From the decoder (3) shown in FIG. 3, a control signal is output as parallel data (27) through the buffer (28) in the signal processing control circuit (4) as a control signal (29) for remote control. By doing so, each unit of the camera is operated.

Further, distance measurement data (145) is output from the control circuit (116) shown in FIG.
Based on this distance measurement data (145), the focus ring (101) shown in FIG. 9A is driven to focus.

As described above, the infrared distance measuring camera of this embodiment receives infrared rays for distance measurement and remote control by one infrared light receiving element, separates them, and performs signal processing by each circuit. Is done. Even if the control signal is received during the distance measuring operation by the signal processing control circuit (4) and the mode judging circuit (31), the distance measuring operation is prioritized and the control signal is processed during the distance measuring operation period. Or, conversely, by preventing processing of the distance measurement signal while receiving the control signal, interference between both signals is prevented,
It is possible to transmit appropriate distance measurement signals and remote control signals.

Further, since the infrared distance measuring camera in this embodiment receives the signals for distance measurement and remote control by one infrared light receiving element as described above,
The installation space is smaller than the case where individual light receiving elements are provided, and it has become possible to perform accurate and reliable distance measurement and remote control operation while realizing downsizing and cost reduction of the camera.

Further, in the above-mentioned embodiment, the configuration example of the signal processing control circuit which fixedly processes the distance measuring operation over the control operation of the remote control is shown. The control operation of the control may be prioritized over the distance measuring operation to perform signal processing.

As a modification, as shown in FIG. 8A, a low-pass filter (30) may be further provided after the differential amplifier (136) in the signal processing / arithmetic circuit (114). Is.

When the camera receives an infrared pulse from the remote controller during distance measurement, the PSD output current I
The outputs of 1 and I2 have a waveform as if the control pulse is superimposed on the distance measurement pulse, as shown in FIG. Then, this is LnI1 and LnI2 by a differential amplifier (136).
Even if the difference is taken, the pulse component may remain as shown in FIG. 7B, and if this is left as it is, a distance measurement error is likely to occur.

Therefore, in the modification shown in FIG. 8A, a low-pass filter (3) having a cutoff frequency at which the control pulse can be removed is provided at the next stage of the differential amplifier (136).
By providing 0), a distance measuring pulse with a small residual control pulse is obtained as shown in FIG.

In this modification, the means for further reducing the adverse effects due to the interference that is likely to occur when the distance measurement signal and the control signal of the infrared remote controller are superposed is adopted, so that malfunctions are further reduced, and distance measurement can be performed reliably. Remote control operation can be performed.

[0075]

As described above, according to the infrared distance measuring camera of the present invention, one infrared light receiving element is used for both distance measurement and control, so that the camera mechanism is simplified.
The camera can be miniaturized. When the distance measurement signal and the control signal are superposed, the mode determination means preferentially processes one of the signals on the basis of the distance measurement / control processing priority information, so that an error or malfunction due to signal interference may occur. It has become possible to prevent it.

[Brief description of drawings]

FIG. 1 is a configuration block diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a signal processing / arithmetic circuit and a control signal detection circuit according to an embodiment of the present invention.

FIG. 3 is a circuit diagram of a decoder according to an exemplary embodiment of the present invention.

FIG. 4 is a circuit diagram of a signal processing control circuit according to an embodiment of the present invention.

FIG. 5 is a circuit diagram showing a control circuit to which a mode determination circuit is added.

FIG. 6 is a waveform chart and timing chart of each part of the control circuit according to the embodiment.

FIG. 7 is a timing chart showing waveforms of various parts of the signal processing control circuit according to the embodiment.

FIG. 8 is a circuit diagram and a waveform diagram of each part of a signal processing arithmetic circuit according to another embodiment.

FIG. 9 is an external view of a conventional home video camera.

FIG. 10 is a block diagram showing a configuration of a conventional example.

11A and 11B are explanatory diagrams of a PSD, FIG. 11A is a plan view thereof, FIG. 11B is a characteristic diagram of output current thereof, and FIG. 11C is an equivalent circuit diagram of the one-dimensional PSD.

FIG. 12 is a diagram showing a relationship between a PSD output and a subject distance.

FIG. 13 is a circuit diagram of a control circuit.

FIG. 14 is a circuit diagram showing an LED drive circuit.

FIG. 15 is a circuit diagram showing a signal processing / arithmetic circuit.

FIG. 16 is a circuit diagram showing a sample / hold and analog / digital conversion circuit.

FIG. 17 is a circuit diagram showing a remote sensor circuit.

FIG. 18 is a circuit diagram and a waveform diagram of each part of the remote sensor circuit.

[Explanation of symbols]

 (1) Infrared remote controller (2) Control signal detection circuit (3) Decoder (4) Signal processing control circuit (31) Mode determination circuit (111) Infrared light receiving element (PSD) (116) Control circuit

Claims (1)

(57) [Claims] 1. A camera body equipped with a mechanism for transmitting and receiving focusing infrared rays for focusing, and a camera body remote control provided separately from the camera body, to which ranging / control processing priority information is added. includes an infrared remote controller for transmitting control information for use in the infrared, and the camera body, and co-infrared light receiving element you receiving a control for infrared from the infrared remote controller and the distance measuring infrared, The distance measurement / control from the output signal of the shared infrared light receiving element
Control information extracting means for extracting the control information including processing priority information ; A mode determining means for determining is provided, and the infrared remote controller side gives priority to distance measurement or control.
An infrared range-finding camera characterized by being able to selectively set the processing priority .